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The electroweak monopole in the standard model, the existence, characteristic features, cosmological production and physical implications are discussed. The discovery of the Higgs particle has been thought to be the ‘final’ test of the standard model. If the standard model is correct, however, it must have the electroweak monopole as the electroweak generalization of the Dirac monopole. This means that the detection of this monopole should become the final and topological test of the standard model. If detected, it becomes the first magnetically charged and stable topological elementary particle in the history of physics. Moreover, it has deep implications in physics. In cosmology, it could generate the primordial magnetic black holes which could explain the dark matter, become the seed of the large-scale structures of the universe, and be the source of the intergalactic magnetic field. Just as importantly, it could generate the hitherto unknown magnetic current which could have huge practical applications. Furthermore, the existence of the monopole requires us to reformulate the perturbative expansion in quantum field theory. This makes the detection of the electroweak monopole a most urgent issue. We discuss useful tips for the MoEDAL detector at LHC and similar experiments on how to detect the monopole successfully. This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

MoEDAL is a pioneering LHC experiment designed to search for anomalously ionizing messengers of new physics, such as the magnetic monopole. After a test run at 8 TeV centre-of-mass energy ( E cm ), it started official data taking at the LHC at an E cm of 13 TeV, in 2015. Its groundbreaking physics program defines a number of scenarios that yield potentially revolutionary insights into such foundational questions as: are there extra dimensions or new symmetries; what is the mechanism for the generation of mass; does magnetic charge exist; do topological particles exist; and what is the nature of dark matter? After a brief introduction, MoEDAL's progress to date will be reported, including its past, current and expected future physics output. Additionally, an upgrade to the MoEDAL detector consisting of two new subdetectors: MAPP (MoEDAL Apparatus for Penetrating Particles) now being prototyped at IP8; and MALL (MoEDAL Apparatus for very long-lived particles), will be presented. Finally, a possible astroparticle extension to MoEDAL, called Cosmic-MoEDAL, will be briefly described. This high altitude detector will allow the search for magnetic monopoles to be continued from the TeV scale to the GUT scale. This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

We briefly discuss non-singular black hole models, with the main focus on the properties of non-singular evaporating black holes. Such black holes possess an apparent horizon, however the event horizon may be absent. In such a case, the information from the black hole interior may reach the external observer after the complete evaporation of the black hole. This model might be used for the resolution of the information loss puzzle. However, as we demonstrate, in a general case the quantum radiation emitted from the black hole interior, calculated in the given black hole background, is very large. This outburst of the radiation is exponentially large for models with the redshift function α = 1. We show that it can be suppressed by including a non-trivial redshift function. However, even this suppression is not enough to guarantee self-consistency of the model. This problem is a manifestation of a general problem, known as the \"mass inflation\". We briefly comment on possible ways to overcome this problem in the models of non-singular evaporating black holes.

This paper suggests a dual-band 28/38 GHz four-element MIMO array based on dual-mode planar monopole antennas for 5G wireless applications. The design structure contains four planar monopole antennas; located at the corners on a 20 × 20-mm 2 size Rogers RO4003 substrate with a dielectric constant of 3.55. The proposed planar monopole antenna has the shape of a crescent. In order to achieve the desired behavior and perfor mance, we engraved two rectangular slots on both sides and also added a notch at the bottom. In addition, we used a partial ground plane to enhance the isolation. Significant isolation (> − 23 dB) is achieved between antenna elements by employing spatial and polarization diversity techniques. To validate the design concept, a prototype of the four-element MIMO array is designed, fabricated, and measured. The experimental results show that the proposed antenna can cover the 27.25–29 GHz and 34.5–41 GHz bands with good isolation and high efficiency. Furthermore, the radiation pattern, the realized gain, and the channel capacity are also studied. According to the reached results, the proposed MIMO antenna may be a suitable application-oriented design for 5G MIMO applications at the millimeter-wave range.

A novel and compact tri-band microstrip-fed monopole antenna with dual-polarisation characteristics for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications is proposed. The antenna is composed of a partial ground and a Y-shaped radiating patch that consists of two unequal monopole arms and a modified circle monopole. The antenna is able to generate three separate impedance bandwidths to cover the frequency bands of the WLAN (2.4–2.484 and 5.8 GHz) and the WiMAX (3.4–3.7 GHz). In addition, the antenna is circularly polarised in both the WLAN bands. Furthermore, the antenna structure is extremely simple, durable and occupies small space, making it suitable for practical applications.

This letter proposes a transparent ultrawideband (UWB) monopole antenna with conformal sparse metal grids. On the one hand, because of the sparse metal grids, the antenna is highly transparent. On the other hand, the sparse grids of the transparent antenna are designed based on the antenna current, which has little influence on the antenna performance. By using the electrohydrodynamics (EHD) technology, the transparent antenna is designed, fabricated and measured. Experimental results agree well with simulations. The transmittance of the proposed UWB antenna reaches 96.4%. Meanwhile, it exhibits a bandwidth of 4–16.3 GHz and achieves an average radiation efficiency of 69.1%.

Flexible titanium carbide (Ti 3 C 2 ) antenna offers a breakthrough in the penetration of information communications for the spread of Internet of Things (IoT) applications. Current configurations are constrained to multi-layer complicated designs due to the limited conformal integration of the dielectric substrate and additive-free Ti 3 C 2 inks. Here, we report the flexible ultrawideband Ti 3 C 2 monopole antenna by combining strategies of interfacial modification and advanced extrusion printing technology. The polydopamine, as molecular glue nano-binder, contributes the tight adhesion interactions between Ti 3 C 2 film and commercial circuit boards for high spatial uniformity and mechanical flexibility. The bandwidth and center frequency of Ti 3 C 2 antenna can be well maintained and the gain differences fluctuate within ±0.2 dBi at the low frequency range after the bent antenna returns to the flat state, which conquers the traditional inelastic Cu antenna. It also achieves the demo instance for the fluent and stable real-time wireless transmission in bending states. Designing ultrathin and flexible antenna is of great interest for efficient wireless data communication and transmission at fast-growing IoT applications. The authors report a flexible ultrawideband Ti 3 C 2 monopole antenna by combining strategies of interfacial modification and advanced extrusion printing technology.

We employ a variety of symmetry breaking patterns in SO(10) and E6 Grand Unified Theories to demonstrate the appearance of topological defects including magnetic monopoles, strings, and necklaces. We show that independent of the symmetry breaking pattern, a topologically stable superheavy monopole carrying a single unit of Dirac charge as well as color magnetic charge is always present. Lighter intermediate mass topologically stable monopoles carrying two or three quanta of Dirac charge can appear in SO(10) and E6 models respectively. These lighter monopoles as well as topologically stable intermediate scale strings can survive an inflationary epoch. We also show the ap­ pearance of a novel necklace configuration in SO(10) broken to the Standard Model via SU(4)c × SU(2)L × SU(2)R. It consists of SU(4)c and SU(2)R monopoles connected by flux tubes. Necklaces consisting of monopoles and antimonopoles joined together by flux tubes are also identified. Even in the absence of topologically stable strings, a monopole-string system can temporarily appear. This system decays by emitting gravity waves and we provide an example in which the spectrum of these waves is strongly peaked around 10−4 Hz with Ωqwh2 ≃10−12. This spectrum should be within the detection capability of LISA.

A bandwidth reconfigurable monopole antenna with disc-shaped is presented in this article. This presented antenna is integrated with a disc-shaped monopole antenna and a cascaded bandpass structure, and four different bandwidth states can be adjusted by the bandpass structure. By switching the diode’s on-off state integrated with the bandpass structure, this presented monopole antenna can switch quickly among four different bandwidth states whose fractional bandwidth is range from 16% to 55% centered at around 1.8 GHz. The experiment also shows good and stable electromagnetic properties of this presented antenna in different working bandwidths.

This paper presents bandwidth enhancement of a monopole antenna by hybridization with cylindrical dielectric resonator (CDR) elements. Dual resonance of the monopole is obtained when the electric current distribution is controlled by adding metallic branches and metallic sphere components. Two prototypes are proposed, incorporating the dual monopole modes and hybrid automatic (HEM) 11δ mode of CDR elements, promising an ultra-wideband (UWB) response with an omnidirectional radiation pattern. The first prototype is composed of two CDRs and a monopole branch which gives an operating bandwidth of 67.25% (6.01–12.1 GHz). The second prototype, with a small metallic sphere-loaded monopole, is surrounded symmetrically by four CDR elements. As a result, the impedance bandwidth is enhanced up to 76.61% (6.2–13.9 GHz). The simulated results including reflection coefficients, radiation patterns, and antenna gains are compared with the experimental results of the fabricated prototype, and good agreement is found between them.